Transmission



Nov. 4, 1947.

' I w. D. TIPTON 2,430,089

TRANSMISSION Filed April 6, 1944 2 Sheets-Sheet 1 Patented Nov. 4,194?

TRANSMISSION William D. Tipton, Stoneleigh, Md.; Elizabeth Barrett Tipton executrlx of said William D.

Tipton, deceased Application April 6, 1944, Serial No. 529,759

This invention relates to automotive transmissions of the semi-automatic self shifting type. I

The principal object of the invention is to provide a, self-shifting vehicle transmission wherein vbodiment is disclosed.

In the drawings accompanying the description,

Fig. 1 is a. schematic showing of the upper half of my improved transmission, certain parts unnecessary to an understanding of the invention such as seals, bearings, valves, etc., being omitted for the sake of clarity.

Fig. 2 is a diagrammatic illustration of certain principles of operation of the Fig. 1 device.

Fig. 3 is a detail of a-counter-weighted pinion as used in the transmission.

Fig. 4 is a complete illustration of the schematic showing .of Fig. 1.

Referring to Fig. 1 it will be seen that a fluid coupling l having an impeller II is drivingly connected to an engine crankshaft I2. which pilots an intermediate shaft l3. The coupling has the usual runner I4 disposed in fluid receiving relation with respect to the impeller I I.

carries at its rear end a sun gear l5. The latter is one elementof a planetary gearset which also includes ring gear l6 and a planet pinion [1. The ring gear I6 is prevented from reverse rotation by means of an overrunning brake I8 of conventional type. The brake I8 is preferably of the roller type and leans against an insidewall 19 of the transmission casing 20.

The pinion I! (of which there are preferably three) has a counterweight 2| carried thereby (see detail in Fig. 3) which is adapted to be acted upon by centrifugal force as a result of rotation of the pinion and revolution thereof about the axis of driven shaft 22. The latter is adapted to be con- 6 Claims. (01. la-189.5)

nected to the vehicle driving wheelsin the usual manner. The pinions I! are mounted on acarrier 23 which is journaled at 23 on shaft 22 and carries a brake drum 24 adapted to be engaged by a. brake band 25. The brake band 25 may be manually controlled by a pedal or it may be automatically controlled by power means in a, manner similar .to that shown in my co-pending application Serial No. 522,735, filed February 1'7, 1944.

The shaft 22. is piloted in the hollow end 26 of the shaft l3 and an overrunning roller clutch 21. is disposed between the two shafts. The clutch 21 is arranged so that it permits the shaft I310 The runner I4 is carried by the shaft l3 which overrun the shaft 22, but prevents the shaft 22 from rotating faster than shaft I3.

Planet carrier 23 carries a sun gear 28 which is an element of a rear planetary gearset. This gearset has a carrier 29 mounting planet pinions 30, the latter having counterweights-3l. The earrier 29 is mounted on the shaft 22 through a fiywheel 32. The latter has relatively great inertia and acts to damp the torque fluctuations in the transmission caused by the counterweights 2| and 3| and prevents transmission of these impulses to the shaft 22.. I

The ring gear 33 of the rear gearset hasv an over-running connection 34 with the casing 20. The connection 34 is preferably of the roller type and prevents reverse rotation of gear 33 while allowing free forward rotation thereof.

The detail in Fig. 3 illustrates the pinion I1 and the counterweight 2|. tical in form.

Operation of the device is as follows: With the car at rest and the engine idling, the

Thepinion30 is iden- -fiuid coupling Ill slips sufliciently to permit the car to remain stationary without creep. An increase in engine speed will cause runner M to rotate at increased speed and apply torque to. the forward planetary gearset.

The brake band 25 is free from the drum 24..

at this time and th torque on sun gear 15 willcause the carrier 23 to be rotated forwardly, the

ring gear [6 being prevented from reverse rotation byfbrake device l8.

Rotation of carrier 23 will, through theintermediary of member 35, cause rotation of sun gear 23 of the rear planetary set. The ring gear 33 of the said rear set is prevented from reverse rotation by brake device 34 therefore the carrier- 3 2i. flywheel .82 and shaft 22 will be rotated driving the vehicle forwardly in low speed ratio, the two reduction gearsets functioning in series.

As the car speeds up and torque diflerence on shafts i8 and 22 diminishes, the driver can effect a shift from low to intermediate speed ratio by ,mornentary release of the engine throttle. This can be understood by reference to Fig. 2. When the engine is supplying torque to shaft 13, planet gears H are urged to rotate through arc ABCD. .-;Tne counterweights 2| set up slight torque fluct-uations which are absorbed in thefluid coupling I 0 since the flywheel 32 resists these fluctuations throughits inertia. When rotating freely with no torque being applied or taken from the gearset, the pinions H and weights 2|, will have some tendency to rotate even though they are under the influence of centrifugal force resulting from the rotation of the carrier 23 about the axis of shaft 22. The torque supplied to the pinions during arc ABC by this centrifugal force is just about suflicient to carry them through arc CDA against centrifugal force. deter this rotation of course and may stop the pinions.

When torque from the engine is applied how- ;ever, the pinions will rotate and continue to ro- Friction, windage, etc., will tate even at low carrier speeds. When the throttle ismomentarily released, the torque through the transmission system is reversed as the car momentarily overruns the engine. This reverses the reaction in the planetary gearset and causes the gear 16 to break away from the housing wall l9 and rotate forwardly as permitted by roller brake 18. The planet pinions i! then slow down and the centrifugal force about the axis of shaft 22 will act on the weights 2] and stop the pinions from rotation about their own axis. Depression of the accelerator to open the throttle will now cause the planetary gearset to rotate as a locked-up unit because the centrifugal force on the weights 2| applied through their rotation about the axis of shaft 22 is suflicient to overcome the tendency for the pinions to rotate. Thus, the forward planetary gearset is "shortcircuited and a step-up in ratio is effected.

At a higher vehicle speed, release of the throttle will cause the rear planetary gearset to lock up in a similar manner and a shift to direct drive is effected.

The forward gearset will lock up first because it rotates faster than the rear set. down to idling speed, as the speed of the lockedup units falls a condition will be arrived at where the torque supplied to the pinions tending to cause thenrto rotate about their own axes is greater than the force on the weights tending to hold them at outer dead center. The respective gearset will start to function and a stepdown in ratio will result. If the two gearsets are identical in ratio it does not matter which one shifts down first. It is probably preferable to provide a-greater ratio change in one of the gearsets than in the other in order to achieve the best accelerating characteristics. If the two sets are made identical in ratio economy is achieved because the parts are interchangeable except for the pinions which must have different counterweights. 7

Overrunning clutch 21 is preferably manually controlled so that it can be thrown into and out of operation by the driver. This device is necessary for starting the engine by towing or push- In coming ing the car. Once the car is moving, centrifugal At very low vehicle speeds the car will freewheel through clutch 21 which is desirable.

It is contemplated that a reverse gear will be used in connection with the transmission but showing thereof has been omitted for the sake of clarity. The brake band 25 may be set to 1. In a vehicle power transmission, a driving shaft; a driven shaft; a planetary gearset having a counterweighted pinion as an element thereof connected between said shafts; fluid clutch means on said driving shaft for absorbing torque fluctuations caused by said pinion and a flywheel on said output shaft for preventing transmission of torque fluctuations thereto.

2. In a vehicle power transmission, an engine driven shaft; a fluid impeller driven by said shaft; a fluid runner driven by said impeller; an intermediate shaft driven by said runner; a sun gear driven by said intermediate shaft; a ring gear; a planet carrier having counterweighted pinions thereon in mesh with said sun and ring gears;

a brake for controlling rotation of said carrier;

an outputshafh'and means including a flywheel for connectingsaid carrier to said output shaft.

3. In a vehicle power transmission, an engine driven shaft; a fluid impeller driven by said shaft; a fluid runner driven by said impeller; an intermediate shaft driven by said runner; a sun gear driven by said intermediate shaft; a ring gear; a planet carrier having counterweighted pinions thereon in mesh with said sun and ring gears; a second sun gear connected to said carrier for rotation therewith; a second ring gear; a secondcarrier having counterweighted pinions thereon'in mesh with said second sun and ring gears; an output shaft, and means connecting said second carrier to said output shaft. I

4. In a'vehicle power transmission, an engine driven shaft; a fluid impeller driven by said shaft; 9. fluid runner driven by said impeller; an intermediate shaft driven by said runner; a sun gear driven by said intermediate shaft; a ring gear; a planet carrier having counterweighted pinions thereon in mesh with said sun and ring gears; a second sun gear connected to said carrier for rotation therewith; a second ring gear; a second carrier having counterweighted pinions thereon in mesh with said second .sun and ring gears; an output shaft, and means connecting said secand carrier to said output shaft including a relatively heavy flywheel member.

5. In a vehicle power transmission, an engine driven shaft; a fluid impeller driven by said shaft; a fluid runner driven by said impeller; an intermediate shaft driven by said runner; a sun gear driven by said intermediate shaft; a ring gear; a planet carrier having counterweighted pinions thereon in mesh with said sun and ring gears; an output shaft. and an inertia member for connecting said carrier to the output shaft.

6. In a vehicle power transmission having an engine driven'shaft and a fluid coupling, a pair of planetary gearsets connected in series between said coupling and the driving means for the vehicle, each of said gearsets having counterweighted planet pinions arranged such that they resist rotation of the gears in said gearsets when subjected to centrifugal force, and shock absorbing means for connecting said gearsets and said driving means.

. WILLIAM D. TIPTON.

REFERENCES CITED The following references are of record in the file of this patent:

Number m Number 

